Semiconductor devices are constantly responding to the market demand for faster, smaller, higher data and less expensive devices. Devices are expected to deliver more functionality at greater speeds in smaller dimensions and with capabilities of electrical and optical signals. This requires a new packaging scheme that can integrate heterogeneous devices such as logic, memory, power, graphics, sensors and other integrated circuits and components in a single package where improved electrical performance is also achieved by having these devices in close proximity.
An example of such packaging scheme is thin glass interposers or through-glass via (TGV) wafers. Thin glass interposers have microscopic through-holes filled with materials that are usually metallized, and can act as connectors between the top and bottom surface of the glass substrate to transfer electronic signals and currents to semiconductor or other devices. These interposers are also very thin, having thicknesses in the micrometer range. The thinness of the thin glass interposers can make them difficult to handle and process, especially when users lack the proper mechanisms to do so.
Applying circuit metallization to one or both side of thin glass interposers is a challenging process. Typically, a sacrificial wafer is attached to a first surface of the thin glass interposer, then the opposing surface is metallized and patterned. Next, the sacrificial wafer is removed and the first surface is processed by metallization, patterning, assembly, etc. This process prolongs the manufacturing time, thereby increasing production costs.
The present invention resolves the above-stated issues by providing a simple, low cost, and potentially reusable method that will allow users to work on the thin glass interposers and similar glass substrates without damaging them. A sacrificial wafer is attached to a first surface that is already metallized, which allows for the opposing surface to be processed while the sacrificial wafer protects the metallized first surface and reinforces the thin glass interposer.
Any feature or combination of features described herein are included within the scope of the present invention provided that the features included in any such combination are not mutually inconsistent as will be apparent from the context, this specification, and the knowledge of one of ordinary skill in the art. Additional advantages and aspects of the present invention are apparent in the following detailed description and claims.